DETROIT — The American Civil Liberties Union is seeking the release of hundreds of people whose deportations to Iraq were suspended but who remain in custody.

The advocacy groups and attorneys representing Iraqi nationals allege in a Tuesday court filing that the government is detaining people without determining whether it’s justified.

Immigration and Customs Enforcement declined to comment Wednesday.

In July, a federal judge in Detroit blocked the deportation of 1,400 people to allow time to challenge their removal in immigration court. Government officials say the detainees have committed crimes in the U.S. and must be deported now that Iraq will accept them. The ACLU says 279 were in jails or detention centers in 26 states at the end of October.

Many are Christians who fear being tortured or killed if deported.